ark: skip refresh when ark unconfigured; document LN listener watchdog

Guard refreshArkWallet against running when config.ark.arkPrivateKey is
unset, and add a comment explaining the ensureListenerAlive watchdog's
zombie-socket recovery.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/ark.ts b/lib/ark.ts
index a37197e8..41515d54 100644
--- a/lib/ark.ts
+++ b/lib/ark.ts
@@ -59,6 +59,7 @@ const withTimeout = <T>(promise: Promise<T>, ms: number, label: string) =>
   ]);
 
 export const refreshArkWallet = async (force = false) => {
+  if (!config.ark?.arkPrivateKey) return; // ark disabled
   const now = Date.now();
   if (refreshing || (!force && now - lastRefresh < REFRESH_COOLDOWN)) return;
   try {